Beef cattle production is based on the cow-calf operation.

There are diverse methods used. In some operations, cows and calves are kept on open pasture and rangeland.

In others, cows and their calves spend most of their time in a confined area for feeding and shelter, whilst having limited access to pasture.

The latter type of partially-confined operation creates filth fly problems which are discussed in this section.

 

 

Production

The categories of cattle in a cow-calf operation are:

1. Dry, mature pregnant cow
2. Cows nursing calves
3. Weanling replacement heifers
4. Bred yearling heifers
5. Growing steers and heifers
6. Herd bulls.

Stalls and areas for feed and water are sites for fly breeding.

Feeding is often accomplished with hay racks which may be covered or open (pictured below and right)

Racks may be fixed on a paved apron or movable. As an alternative to a hay rack, a solid-bottom bunk for hay and silage may be used. Bunks are also needed to feed grain and minerals.

Since calves require a different nutrient composition in their diet, they are fed in a facility which excludes the brood cows. Such a facility is called a creep (pictured below).

A creep in the fenceline restricts grazing.

Movable grain creep feeders (usually on skids) may be used. Although arrangements vary, the creep feeder basically consists of some kind of fenced area or structure with openings of about 1m by 40cm wide which allow access only by calves.

In the creep feeder, calves have access to high nutrient feeds, including feed grain, molasses and protein supplements. Spillage from these feeders and wet feed in the feeders can provide prolific fly breeding areas.

In addition to feed, there has to be an ample supply of drinking water in a cow-calf operation.

In typical summer weather, cows and heifers require 40–56 litres of water per day, while nursing calves require 64–68 litres.

Calves drink about 8% of their body weight per day in the winter and up to 19% in the summer.

The resulting urine mixed with feces and spilled feed provides ample substrate for fly breeding when the animals are confined in high densities.

 

 

Feedlot Finishing

Calves produced in the cow-calf operation may be kept for various lengths of time according to the need for replacement and market conditions.

Calves are fed on either pasture and hay, grain and pasture, or corn silage, for long enough to bring them up to 270–380kg each (about 6 months).

This is known as backgrounding or growing, after which calves are assembled into reasonably uniform groups and sold to feedlots.

Calves may be kept longer (1 year) and sold to feedlots at 320–360kg each.

On feedlots, the cattle are finished. In other words, brought up to market weight on a diet of silage and protein supplements. Alternatively, finishing may be on grain and pasture.

The finishing of cattle on feedlots is a very high-density confined-animal system.

Cattle are grouped by type, age, sex, and weight in outdoor pens and provided with feed and water.

Many pens are grouped together into a single feedlot operation, and conditions are ideal for fly breeding: large accumulations of manure, ample moisture from urine, rain and watering devices, and nutrient-rich feed which is often spilled around the feed bunkers.

Wet area in the edge of a stable, not trampled by cattle and suitable for fly breeding.	Feedlot runoff into low area suitable for fly breeding.	Edge of concrete apron of feed bunker where fly breeding may occur.

Major problem areas for fly breeding are spilled feed mixed with manure under the feed bunkers, and runoff areas where water and manure drains into depressions.

Base of fence line where manure accumulation may support fly breeding.	Manure under raised feed bunker where fly breeding may occur.	Waterer in feedlot with wet manure around base - fly breeding may occur.

Pens for housing sick animals have bedding and also provide a habitat for the development of flies, especially house flies and stable flies.

 

 

Silage

Cow-calf and feedlot operations usually use silage as part of the animal feed.

Silage (chopped corn) is stored in either tower silos (which may be gastight or stave types), or in horizontal trenches or bunkers.

Horizontal storage bunkers may be concrete-lined, but are often just trenches in the ground. The silage is packed and covered with plastic sheeting.

The margins of improperly packed and covered silage provide conditions favorable for fly breeding in horizontal storage systems.

Spillage around the base of tower storage facilities likewise provides a habitat for fly breeding.

Sometimes the silage is piled above ground without proper compacting and covering to suppress fly breeding.

 

 

Hay

The use of hay can contribute to fly production.

There has been an increased use of large round bales of hay which can be moved by tractor-mounted equipment.

The margins of these bales, stored outdoors, provide a suitable habitat for fly breeding after rain, or after the bales have sat on moist ground for a long period of time.

The pad of hay which is often left on the ground after moving the bales provides an excellent habitat for fly breeding.

To prevent fly breeding, hay bales should be covered and stored on pallets to raise them above the ground.